Specific recognition of the Bacillus subtilis gnt cis-acting catabolite-responsive element by a protein complex formed between CcpA and seryl-phosphorylated HPr

Catabolite repression of various Bacillus subtilis catabolic operons which carry a cis-acting catabolite-responsive element (CRE), such as the gnt operon, is mediated by CcpA, a protein belonging to the GalR-Lacl family of bacterial transcriptional repressors/activators, and the seryl-phosphorylated form of HPr, a phosphocarrier protein of the phosphoenolpyruvate:sugar phosphotransferase system. Footprinting experiments revealed that the purified CcpA protein interacted with P-ser-HPr to cause specific protection of the gnt CRE against DNase I digestion. The specific recognition of the gnt CRE was confirmed by the results of footprinting experiments using mutant gnt CREs carrying one of the following base substitutions within the CRE consensus sequence: G to T at position +149 or C to T at position +154 (+1 is the gnt transcription initiation nucleotide). The two mutant CREs causing a partial relief from catabolite repression were not protected by the CcpA/P-ser-HPr complex in footprinting experiments. Based on these and previous findings, we propose a molecular mechanism underlying catabolite repression in B. subtilis mediated by CcpA and P-ser-HPr.

Effect of antiepileptic drugs on absence-like seizures in the tremor rat

We examined the effects of conventional antiepileptic drugs (AEDs) on absence-like seizures in homozygous tremor rats (tm/tm) to determine if they corresponded pharmacologically to human absence seizures and absence-like seizures in spontaneously epileptic rats (SER: zi/zi, tm/tm) with both tonic convulsive and absence-like seizures. Cortical and hippocampal EEG activity was recorded with chronically implanted electrodes. The effects of AEDS on seizures of the tremor rat showed profiles similar to those observed in human absence seizures and also in absence-like seizures of SER. The absence-like seizures, associated with paroxysmal bursts of 5-7-Hz spike-wave complexes, were inhibited by trimethadione (TMO 200 mg/kg intraperitoneally, i.p.), ethosuximide (ESM 100 and 200 mg/kg, i.p.), valproate (VPA 100 mg/kg, i.p.), and phenobarbital (PB 10 and 20 mg/kg, i.p.). Phenytoin (PHT 20 mg/kg, i.p.) was ineffective. These results are consistent with the conclusion that the tremor rat is a useful model for evaluating new AEDS for human absence seizures.

Action of phenolic antioxidants on various active oxygen species

The action of phenolic antioxidants, such as probucol, on various active oxygen species was investigated using luminol chemiluminescence and spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The various active oxygen species, including hydroxyl radicals (Fenton reaction), superoxide anions, singlet oxygen and hypochlorite ions were examined with phenolic antioxidants under aqueous and nonaqueous conditions. Probucol showed a quenching effect on both superoxide anions and hypochlorite ions in nonaqueous solution. However, it had no effect on hydroxyl radicals. alpha-Tocopherol, a natural phenolic antioxidant, showed a stronger quenching effect on superoxide anions and hypochlorite ions than probucol, and quenched hydroxyl radicals in nonaqueous solution. Furthermore, Trolox showed a quenching effect on all active oxygen species in both aqueous and nonaqueous solution. The antioxidants were studied under comparable conditions in a series of test systems and the reactivity profiles depicted as 'radar charts' which are helpful for characterizing antioxidant action.

Effect of the antiretroviral agent hypericin on rat liver mitochondria

The photosensitizing effect of hypericin (HY), an antiretroviral agent, on the functions of isolated rat liver mitochondria has been investigated. The respiratory control ratio (RCR), ADP/O and membrane potential of mitochondria were decreased by HY in a light-dependent manner. Uncoupled respiration of mitochondria in the presence of succinate was also inhibited by HY in a light-dependent manner. The ID50 of hypericin for these inhibitions was approximately 0.5 microM. These inhibitory effects of HY were not observed when photosensitization was conducted under anaerobic conditions and were not affected by desferrioxamine (DSF) or superoxide dismutase (SOD). Upon photosensitization of HY, mitochondria consumed oxygen in the absence of respiratory substrate with concomitant formation of thiobarbituric acid reactive substance (TBARS). The amount of oxygen consumed was 100-times greater than that of TBARS formed. The oxygen uptake was partially inhibited by NaN3, and formation of TBARS was inhibited by DSF. Upon photosensitization of HY in the presence of mitochondrial membranes, the electron spin resonance (ESR) signal of 2,2-dimethyl-5-hydroxy-1-pyrrolidinyloxyl (DMPO/.OH) was increased by a mechanism which was suppressed by DSF. An ESR signal for singlet oxygen bound to 2,5-dimethylfuran, 2,2,6,6-tetramethyl-4-piperidone (TEMP) was also detected under light in the presence of mitochondria. This signal of the TEMP-N-oxyl radical (TEMPO) was decreased by azide, which physically quenches singlet oxygen, but was increased by DSF. These results indicate that HY might inhibit mitochondrial functions by a type II photodynamic mechanism but that lipid peroxidation of biological membranes through an active oxygen-mediated photodynamic mechanism is not involved.

Bacillus subtilis gnt repressor mutants that diminish gluconate-binding ability

The Bacillus subtilis gnt operon is negatively regulated by GntR, which is antagonized by gluconate. Three GntR mutants with diminished gluconate-binding ability were obtained. Two were missense mutants (Met-209 to Ile and Ser-230 to Leu), whereas the third had a deletion of the C-terminal 23 amino acids. The mutant GntR proteins were unable to become properly detached from the gnt operator even in the presence of gluconate.

[The mode of excitation of cat motoneurons]

1. Effects of afferent nerve stimulation on the waveform of the IS-spike were studied intracellularly in 101 motoneurons of cats which were either anesthetized with sodium pentobarbitone or decerebrated at the intercollicular level. 2. In 78 motoneurons repetitive or double shock stimulation of afferent nerves (the L 7 or S 1 dorsal root, biceps-semitendinosus nerve and tibial nerve) could produce 2-4 kinds of IS-spikes, as distinguished by differences in waveform. In 34 motoneurons 2-3 small potentials were superimposed on the smallest IS-spike with progressively longer latencies to form a larger IS-spike. These potentials were thought as dendritic in origin because only the dendrites are known to be capable of exhibiting multiple spikes and in 14 motoneurons dendritic spikes were actually shown to exist. 3. In 13 motoneurons following a repetitive stimulation of a dorsal root there occurred an increase in excitability of the membrane generating the IS-spike (the IS-membrane) in the absence of any appreciable changes in the resting membrane potential. This would indicate that the IS-membrane is subject to plastic changes or the IS-spike itself also originates in dendrites which are known to exhibit such changes.

Developmental changes in P300 wave elicited during two different experimental conditions

Age-related correlations on auditory event-related potentials were studied using a task-relevant oddball paradigm in 175 normal subjects aged 4-21 years and age-related correlations in the "ignore" condition were studied in 108 normal subjects aged 1-21 years. In the ignore condition, subjects more than 4 years of age were instructed to read a book to divert attention from the auditory stimulus. From 4 to about 17 years of age, the latencies of task-relevant P300 in event-related potentials (ERPs) gradually shortened. In the ignore condition experiment, the P300 latency shortened progressively, but stabilized at about 12 years of age. Whereas P300 in the ignore condition likely corresponds to P3a described previously (passive attention), the conventional P300 wave corresponds to P3b (active attention). The findings indicate a developmental difference between the P3a and P3b potential.

A family with hereditary serum cholinesterase deficiency

A family with serum cholinesterase (SChE) deficiency is reported. A 64-year-old woman was admitted for the excision of colon adenoma; her laboratory data revealed a markedly decreased level of SChE. SChE genes of the patient and her family members were amplified by the polymerase chain reaction (PCR) and analyzed by direct sequencing. The patient's SChE gene had a homozygous frame shift mutation, in which an extra adenine was inserted in codon 315 (ACC-->AACC), resulting in the appearance of a new stop codon in codon 322. The family study disclosed that her brother and sister had the same frame shift mutations in homozygote and heterozygote, respectively.

[Chylomicron and VLDL metabolism in daunomycin-induced nephrotic rats]

Lipid metabolism in chylomicron and VLDL were examined in daunomycin-induced nephrotic rats. 1) There was no difference in intestinal cholesterogenesis between the control rats and daunomycin-induced nephrotic rats. 2) The apoprotein content of chylomicron and VLDL increased in daunomycin-induced nephrotic rats. 3) Daunomycin-induced nephrotic rats showed increases in the content of apo B-48 and C-III, and a decrease in that of apo E in chylomicron. The apoprotein composition of VLDL in daunomycin-induced nephrotic rats showed increased apo B and decreased apo E. These results suggest that increased chylomicron-cholesterol is not due to increased intestinal cholesterogenesis, but to decreased chylomicron catabolism in daunomycin-induced nephrotic rats. Increased apoprotein in VLDL may contribute to the decreased catabolism by reducing LPL activity in the plasma and increased secretion from the liver of daunomycin induced nephrotic rats.

Dermoid cyst of the frontal bone away from the anterior fontanel

A case with a midline dermoid cyst of the frontal bone away from the anterior fontanel is reported. Although a few such cases have been reported, detailed descriptions are not given. Possible intracranial extension of these lesions is discussed with review of the pertinent literature.

Surgery for cavoatrial extension of malignant tumors

Surgical management for cavoatrial involvement of malignant tumors and its outcome is reported on for 6 patients; their age ranged from 55 to 79 years and 5 were male and 1 female. The basic disease was renal cell carcinoma in 5 cases and adrenal leiomyosarcoma in 1. Intracaval tumor extension was diagnosed by computed tomography, magnet resonance imaging, digital subtraction angiography, and echocardiography. The tumor was resected together with adherant vena cava and invaded right-atrial wall, using cardiopulmonary bypass and normo- or mild-hypothermia in 5 patients. The caval defect needed to be reconstructed with a slit GORE-TEX vascular prosthesis in 3 patients. In all patients the tumor resections were successful and without major complications. All patients survived and are well from 4 to 52 months after the surgery. It is concluded that such cavoatrial extensions of malignant tumors can be safely and accurately resected with the aid of cardiopulmonary bypass, with favorable early and late outcomes in patients who have no distant metastatic lesions.

Characterization of T cell epitopes restricted by HLA-DP9 in streptococcal M12 protein

Interaction of the HLA-DP9 (DPA1*0201/DPB1*0901) molecule and M protein of serotype 12 (SS95/12) streptococci, a main component of the streptococcal cell wall Ag, has been investigated to decipher peptide-binding capacity and T cell activation in the context of the HLA-DP molecule. Seven antigenic peptides (amino acids 19-25) restricted by the HLA-DP9 molecule were identified in M12 protein, using M12 protein- or peptide-specific T cell lines from naturally exposed individuals. The binding affinity of each peptide to the HLA-DP9 molecule was measured by fluorescence intensity of biotinylated peptides bound to L cell transfectants expressing HLA-DP9, followed by treatment with avidin-fluorescence. Binding of biotinylated peptides to the HLA-DP9 molecule was inhibited by an excess amount of corresponding nonbiotinylated peptides and other nonbiotinylated peptides, indicating that the peptides were bound to the HLA-DP9 molecule at a single binding site. Seven synthetic peptides containing the T cell epitopes restricted by the HLA-DP9 molecule had high binding affinity to the HLA-DP9 molecule. Comparison of the amino acid sequences of truncated analogues that could bind to the HLA-DP9 molecule and/or activate T cells suggested an HLA-DP9-specific binding motif, composed of a positively charged residue (R or K) at position 1, a hydrophobic residue (A, G, or L) at position 6, and another hydrophobic residue (L or V) at position 9. Analysis of single amino acid-substituted analogues suggested that the positively charged amino acid in the motif served as a key anchor residue for binding to the HLA-DP9 molecule, which differs from the binding motif to the HLA-DR molecules.

[Effectiveness of haloperidol in the treatment of chorea minor]

Chorea minor is the most curious manifestation of rheumatic fever, first described by Sydenham in 1686. Subsequent evidence showed that chorea could be a late manifestation of rheumatic fever, often occurring several months after a streptococcal infection in contrast to other major manifestations. During the ten-year period between 1984 and 1993, 11 children with rheumatic fever were seen at our hospital, two cases of these being accompanied with chorea minor. Case 1, a male aged 12, presented with involuntary movements. He was diagnosed as having rheumatic fever because of chorea and systolic ejection murmur at the apex of the heart. Plain cranial CT was normal. However, positron emission computed tomography revealed an increased 11C-glucose uptake in the caudate nucleus as compared with the cerebral cortex. Case 2, a female aged 14, presented with involuntary movements. Plain cranial CT was normal, but single photon emission CT showed a difference between the right and left brain. These two patients were given penicillin G (PCG), predonisolone (PSL) and haloperidol. Haloperidol was administered, because PCG and PSL had no effect to improve the clinical manifestations. After administer decreased to a half with a clinical improvement, but the level of GABA did not change. Haloperidol seemed to be an effective and useful agent for motor manifestations of the disease.

Characterization of T cell epitopes restricted by HLA-DP9 in streptococcal M12 protein

Interaction of the HLA-DP9 (DPA1*0201/DPB1*0901) molecule and M protein of serotype 12 (SS95/12) streptococci, a main component of the streptococcal cell wall Ag, has been investigated to decipher peptide-binding capacity and T cell activation in the context of the HLA-DP molecule. Seven antigenic peptides (amino acids 19-25) restricted by the HLA-DP9 molecule were identified in M12 protein, using M12 protein- or peptide-specific T cell lines from naturally exposed individuals. The binding affinity of each peptide to the HLA-DP9 molecule was measured by fluorescence intensity of biotinylated peptides bound to L cell transfectants expressing HLA-DP9, followed by treatment with avidin-fluorescence. Binding of biotinylated peptides to the HLA-DP9 molecule was inhibited by an excess amount of corresponding nonbiotinylated peptides and other nonbiotinylated peptides, indicating that the peptides were bound to the HLA-DP9 molecule at a single binding site. Seven synthetic peptides containing the T cell epitopes restricted by the HLA-DP9 molecule had high binding affinity to the HLA-DP9 molecule. Comparison of the amino acid sequences of truncated analogues that could bind to the HLA-DP9 molecule and/or activate T cells suggested an HLA-DP9-specific binding motif, composed of a positively charged residue (R or K) at position 1, a hydrophobic residue (A, G, or L) at position 6, and another hydrophobic residue (L or V) at position 9. Analysis of single amino acid-substituted analogues suggested that the positively charged amino acid in the motif served as a key anchor residue for binding to the HLA-DP9 molecule, which differs from the binding motif to the HLA-DR molecules.

[Change in the treatment procedures for mitral valve disease]

This study investigated the changes in treatment procedures for mitral stenosis (MS) and mitral regurgitation (MR) against the background of a decrease in the incidence of rheumatic valvular disease. The study included 3,955 patients with MS undergoing closed mitral commissurotomy (CMC), open mitral commissurotomy (OMC), mitral valve replacement (MVR), or percutaneous transvenous mitral commissurotomy (PTMC) between 1952 and 1991, and 478 patients with MR undergoing MVR or mitral valvuloplasty in the Heart Institute of Japan, Tokyo Women's Medical College. The number of patients with MS undergoing surgical or catheter interventions has decreased and is now about 80 per year, a half of that experienced in the 1960s. CMC and OMC have been replaced by PTMC since the 1990s. The most popular treatment procedure is now MVR. The number of patients with MR undergoing surgery has increased to about 30 per year. Eighty percent of operations for MR are MVR and the others are mitral valvoplasty. Survey of the etiology of MR shows decreased rheumatic disease and increased degenerative disease. The incidence of MR due to ischemic heart disease and hypertrophic obstructive cardiomyopathy has slightly increased.

Partial purification and characterization of an esterase acting on the anticancer pro-drugs, 7-ethylcamptothecin derivatives

A hydrolytic enzyme which catalyzes hydrolysis of the ester-linkage of a series of 17-O-acyl derivatives of 7-ethylcamptothecin-21-(2-dimethylamino)ethylamide [acyl derivatives of 22E] was purified from rat liver and its properties were characterized. It hydrolyzed the ester-linkage of all 22E derivatives tested as well as p-nitrophenyl acetate at pH 8-9 but had no effect on 7-ethyl-10-[4-(piperidino)-1-piperidino] carbonyloxycamptothecin (CPT-11: irinotecan), unlike CPT-11 converting carboxylesterase, which was previously purified from rat serum [Tsuji T. et al., J. Pharmacobio-Dyn., 14, 341 (1991)]. The enzyme had no effect on either acetyl choline or butyrylcholine. It was inhibited by several organophosphorous compounds such as diisopropyl fluorophosphate (DFP), bis-(p-nitrophenyl)phosphate and paraoxon, but was insensitive to inhibitors specific for choline esterases. These results indicate that this liver esterase is clearly distinct from choline esterase and serum CPT-11 converting enzyme and is able to convert pro-drugs, O-acyl derivatives of 22E, to an antitumor agent.

Molecular cloning and nucleotide sequence of the protyrosinase gene, melO, from Aspergillus oryzae and expression of the gene in yeast cells

The coding region of the protyrosinase gene, melO, from Aspergillus oryzae occupies 1671 base pairs of the genomic DNA and is separated into two exons by one intron. The full-length cDNA of the melO gene was cloned. Analysis of the 1617 base pairs nucleotide sequence revealed a single open reading frame coding 539 amino acid residues. The cDNA has been expressed in yeast cells. The predicted protein product derived from the melO gene is identified by Western blotting and activity determination. The predicted amino acid sequence of the gene product was compared with that of Neurospora crassa tyrosinase. A coupled pair of three histidine residues in the tyrosinase was assumed to correspond to Cu(II) ligands in the homologous tyrosinases from Streptomyces glaucescens and Homo sapiens.

[Clinical significance of transesophageal echocardiography for evaluation of patients after Bentall's operation: detection of graft failure]

Leakage from the composite graft at the site of coronary anastomosis into the perigraftal space (pseudoaneurysm) is an important complication of Bentall's operation. The clinical value of transesophageal echocardiography (TEE) for detecting this graft failure was evaluated in 30 patients who underwent Bentall's operation or Piehler's modification. Three patients (10%) had perigraftal leakage (pseudoaneurysm). TEE demonstrated the leakage site which was not clearly showed by computed tomography (CT) scan and aortography. The detection rate of the anastomosed native coronary artery was 89% (left: 100%, right: 67%). Interposition graft by Pichler's modification method was detected in 96% (left: 100%, right: 92%) of cases by TEE, but only in 43% (left: 57%, right: 29%) by CT scan (left: p < 0.005, right: p < 0.0001). The detection rate of the right coronary artery, interposition graft to right coronary artery, and their color signals were lower than those of the left coronary artery. TEE has considerable diagnostic value in evaluating patients after Bentall's operation.

Cloning and sequencing of a 29 kb region of the Bacillus subtilis genome containing the hut and wapA loci

Within the framework of an international project for the sequencing of the entire Bacillus subtilis genome, a 29 kb chromosome segment, which contains the hut operon (335 degrees) and the wapA gene, has been cloned and sequenced. This region (28,954 bp) contains 21 complete ORFs and one partial one. The 5th, 6th and 17th genes correspond to hutH encoding histidase, hutP encoding the positive regulator for the hut operon and wapA encoding a precursor of three major wall-associated proteins, respectively. A homology search for their products deduced from the 21 complete ORFs revealed that nine of them exhibit significant homology to known proteins such as urocanase (Pseudomonas putida), a protein involved in clavulanic acid biosynthesis (Streptomyces griseus), amino acid permeases (lysine, Escherichia coli; histidine, Saccharomyces cerevisiae; and others), beta-glucoside-specific phosphotransferases (E. coli and Erwinia chrysanthemi) and 6-phospho-beta-glucosidases (E. coli and Erw. chrysanthemi). Based on the features of the determined sequence and the results of the homology search, as well as on genetic data and sequence of the hut genes reported by other groups, it is predicted that the B. subtilis hut operon may consist of the following six genes (6th-1st), the last of which is followed by a typical rho-independent transcription terminator: hutP, hutH, EE57A (hutU) encoding urocanase, EE57B (hutI) encoding imidazolone-5-propionate hydrolase, EE57C (hutG) encoding formiminoglutamate hydrolase and EE57D (tentatively designated as hutM) possibly encoding histidine permease. Interestingly, the direction of transcription of these hut genes is opposite to that of the movement of the replication fork.